1. Field of the Invention
The present invention relates to an optical integrated circuit that integrates an image pickup device (for use with a video camera or an electronic camera) and a peripheral circuit.
2. Description of the Related Art
FIGS. 7A and 7B show an IC chip for a conventional charge coupled device (CCD) as an image pickup device. The CCD comprises photo diodes 71, a horizontal CCD transferring portion 72, a vertical CCD transferring portion 73, and a signal outputting portion 74. As shown in FIG. 8, the CCD is housed in a ceramics package 81. Electrode pads of the CCD are connected with wire bonds 82. The resultant structure is packaged with a cover glass 83. As shown in FIG. 9, a CCD camera comprises a light receiving portion 91, a CCD 92, a signal processing IC 93, a CCD driving IC 94, and a noise processing IC 95.
An MOS type sensor that had been used for an image pickup device as with a conventional CCD has been attractive because of improvements in sensitivity, S/N ratio, and so forth. Unlike with the conventional CCD, since the CMOS sensor can be fabricated in a conventional IC fabricating process, as shown in FIG. 10, an image pickup device 101 and peripheral circuits 102 to 107 are integrated as a one chip IC. Thus, when this IC is used for a video camera, the size thereof can be decreased.
When electrode pads P are disposed to the IC that integrates the image pickup portion 101 and the peripheral circuits 102 to 107 by the wire bond method as shown in FIG. 7, impedance of each of power supply and ground of the internal circuits rises due to the influence of internal line connections. Thus, various problems such as noise and signal crosstalk take place.
In addition, when bare chips as shown in FIG. 11 are mounted in the state that the electrode pads are disposed on the periphery of ICs (as in Japanese Patent Laid-Open Application No. 7-99214), the size of a cover glass 101 becomes large. Thus, the cost rises and optical accuracy deteriorates. In addition, as shown in FIG. 12, light L that enters through the cover glass 101 internally reflects on a peripheral portion 122 of an image pickup portion 121 of a CCD 112. Thus, a ghost may take place in the resultant picture contains a ghost.
As described above, in the conventional optical integrated circuit apparatus, impedance of each of power supplies and ground of internal circuits rises due to the influence of internal line connections thereof. Thus, various problems such as noise and signal crosstalk take place. In addition, the size of the cover glass becomes large and the cost rises. Moreover, the optical accuracy deteriorates.